From: Dirk Eibach eibach@gdsys.de
Add support for Atmel TPM devices with two wire interface.
Signed-off-by: Dirk Eibach dirk.eibach@gdsys.cc Signed-off-by: Reinhard Pfau reinhard.pfau@gdsys.cc --- Changes in v7: None Changes in v6: - rename CONFIG_ATMEL_TWI_TPM to CONFIG_TPM_ATMEL_TWI - rename drivers/tpm/atmel_twi_tpm.c to drivers/tpm/tpm_atmel_twi.c - replace DEBUG_ATMEL_TWI_TPM, simply use DEBUG - sort drivers/tpm/Makefile - timeout on waiting for TPM reply
Changes in v5: None Changes in v4: None Changes in v3: None Changes in v2: None
README | 3 ++ drivers/tpm/Makefile | 1 + drivers/tpm/tpm_atmel_twi.c | 121 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 125 insertions(+) create mode 100644 drivers/tpm/tpm_atmel_twi.c
diff --git a/README b/README index 3f9a613..2fa8c1e 100644 --- a/README +++ b/README @@ -1225,6 +1225,9 @@ The following options need to be configured: CONFIG_TPM_TIS_I2C_BURST_LIMITATION Define the burst count bytes upper limit
+ CONFIG_TPM_ATMEL_TWI + Support for Atmel TWI TPM device. Requires I2C support. + CONFIG_TPM_TIS_LPC Support for generic parallel port TPM devices. Only one device per system is supported at this time. diff --git a/drivers/tpm/Makefile b/drivers/tpm/Makefile index 913dd9c..c3010ba 100644 --- a/drivers/tpm/Makefile +++ b/drivers/tpm/Makefile @@ -26,6 +26,7 @@ LIB := $(obj)libtpm.o $(shell mkdir -p $(obj)slb9635_i2c)
# TODO: Merge tpm_tis_lpc.c with tpm.c +COBJS-$(CONFIG_TPM_ATMEL_TWI) += tpm_atmel_twi.o COBJS-$(CONFIG_TPM_TIS_I2C) += tpm.o COBJS-$(CONFIG_TPM_TIS_I2C) += tpm_tis_i2c.o COBJS-$(CONFIG_TPM_TIS_LPC) += tpm_tis_lpc.o diff --git a/drivers/tpm/tpm_atmel_twi.c b/drivers/tpm/tpm_atmel_twi.c new file mode 100644 index 0000000..361a772 --- /dev/null +++ b/drivers/tpm/tpm_atmel_twi.c @@ -0,0 +1,121 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <tpm.h> +#include <i2c.h> +#include <asm/unaligned.h> + +#define ATMEL_TPM_TIMEOUT_MS 5000 /* sufficient for anything but + generating/exporting keys */ + +/* + * tis_init() + * + * Initialize the TPM device. Returns 0 on success or -1 on + * failure (in case device probing did not succeed). + */ +int tis_init(void) +{ + return 0; +} + +/* + * tis_open() + * + * Requests access to locality 0 for the caller. After all commands have been + * completed the caller is supposed to call tis_close(). + * + * Returns 0 on success, -1 on failure. + */ +int tis_open(void) +{ + return 0; +} + +/* + * tis_close() + * + * terminate the currect session with the TPM by releasing the locked + * locality. Returns 0 on success of -1 on failure (in case lock + * removal did not succeed). + */ +int tis_close(void) +{ + return 0; +} + +/* + * tis_sendrecv() + * + * Send the requested data to the TPM and then try to get its response + * + * @sendbuf - buffer of the data to send + * @send_size size of the data to send + * @recvbuf - memory to save the response to + * @recv_len - pointer to the size of the response buffer + * + * Returns 0 on success (and places the number of response bytes at recv_len) + * or -1 on failure. + */ +int tis_sendrecv(const uint8_t *sendbuf, size_t send_size, uint8_t *recvbuf, + size_t *recv_len) +{ + int res; + unsigned long start; + +#ifdef DEBUG + memset(recvbuf, 0xcc, *recv_len); + printf("send to TPM (%d bytes, recv_len=%d):\n", send_size, *recv_len); + print_buffer(0, (void *)sendbuf, 1, send_size, 0); +#endif + + res = i2c_write(0x29, 0, 0, (uchar *)sendbuf, send_size); + if (res) { + printf("i2c_write returned %d\n", res); + return -1; + } + + start = get_timer(0); + while ((res = i2c_read(0x29, 0, 0, recvbuf, 10))) { + if (get_timer(start) > ATMEL_TPM_TIMEOUT_MS) { + puts("tpm timed out\n"); + return -1; + } + udelay(100); + } + if (!res) { + *recv_len = get_unaligned_be32(recvbuf + 2); + if (*recv_len > 10) + res = i2c_read(0x29, 0, 0, recvbuf, *recv_len); + } + if (res) { + printf("i2c_read returned %d (rlen=%d)\n", res, *recv_len); +#ifdef DEBUG + print_buffer(0, recvbuf, 1, *recv_len, 0); +#endif + } + +#ifdef DEBUG + if (!res) { + printf("read from TPM (%d bytes):\n", *recv_len); + print_buffer(0, recvbuf, 1, *recv_len, 0); + } +#endif + + return res; +}